I like everything about the AeroPress; however, I noticed that I exhibited symptoms which I usually only have when I've consumed too much caffeine.
So instead of using two scoops during preparation per instructions, I scaled down to one. That seemed to help, but not enough--if I use the same coffee and amount in a conventional coffeemaker and consume it all in one sitting, I don't feel over-stimulated.
Does the AeroPress simply make "stronger" coffee with regards to caffeine content?
Aeropress coffee (hearby called Aerpresso in this post) is more concentrated than regular drip coffee. However, if you are using similar amounts of grounds as you would in a drip machine, you shouldn't notice any difference. Caffeine is highly soluble in hot water and most any extraction method utilizing hot water will result in nearly full extraction of caffeine from grounds.
Aerpresso ends up somewhere in caffeine concentration between espresso (very concentrated) and drip coffee (less concentrated). However, the total amount of caffeine is dependent more on the amount of grounds used that the extraction method (with the above listed methods).
So the the final answer is no. There isn't more caffeine, but the Aerpresso is more concentrated.
This is an intriguing question which I wanted to ask myself. From what I could gather, there are two points here, one theoretical and one empiric.
As far as I know, caffeine is one of the fastest-extracting compounds in coffee, such that it is extracted almost immediately, so, logically, the amount of caffeine in a brew would only be determined by the amount of beans that go into it and not the brewing method. Which means that whatever comes out of the AeroPress could not possibly have that much more caffeine than other methods. Particularly, not significantly more than an espresso shot, since the amounts of coffee used are about the same.
My own experience, however, suggests otherwise. When I first got my AeroPress, I (naturally) brewed some coffee with it. Upon drinking just half of the brew, I got a kick stronger than after anything I'd ever consumed before. Several days later I hosted a party where I served AeroPress coffee, and about two thirds of the guests independently noted that the coffee was unusually strong.
Solving this contradiction seems pretty hard. Right now I see several (not entirely exclusive) possibilities:
second, that AeroPress brew contains high concentrations of some non-caffeine compounds, which:
I don't know how likely this is, since I'm not aware of whether caffeine is the only major contributor to the effects of coffee.
finally, that it is mainly a placebo-like psychological effect. Also unlikely, since the guests at the party probably did not have any prior preconceptions about AeroPress coffee.
Bottom line: coffee from the AeroPress does tend to be perceived as stronger than average by a variety of people (including stronger after-coffee effects), but caffeine might not be the reason.
I believe that pressurizing coffee beans extracts more caffeine. Espresso is steamed under pressure and produces very strong coffee and an old billetti maker boils and pressurizes the beans upwards. I think that depending on the time you let the grounds steep and how hard you press the aero press you will get different results on caffeine strength. I also don't think there is a way to be consistent since sometimes the filter is clogged and sometimes you push harder or softer. Still tastes great either way.
Well, for me: I'd say aeropress has more caffeine in it only if you're using filter-roast beans which I think is what you should be using, and most importantly it depends on the amount of coffee you are putting (coffee to water [91°C] ratio as well as time [a minute or two, max]). In that case, you'll get more kick of caffeine, cleaner finish, yet not stronger than the regular brewed or drip coffee in regards to how long you steep it unless you consider the kick of an overly extracted coffee strong.
